Observed Seismicity - University of Kentucky

Discussion
9
Figure 9. Seismic recordings of the Bardwell event from station BLKY.
Table 4. Comparison of parameters of the Bardwell, Ky., and Blytheville, Ark., earthquakes.
Date Time Magnitude Location Focal Depth
(EDT) (M w
) (La./Lo.) (km)
06/06/2003 8:29:34 a.m. 4.0 36.88N/88.98W 2.3
04/30/2003 0:56:22 a.m. 4.0 35.92N/89.92W 23.8
The observed seismicity between January
and June 2003 in the New Madrid Seismic
Zone indicates that (1) most recorded
seismicity in the central United States reflects
the active faults of the New Madrid Seismic
Zone and (2) in the Jackson Purchase Region,
characteristics of earthquakes, such as focal
depth, are different from those of earthquakes
in the central New Madrid Seismic
Zone. Six months of seismic monitoring is
not enough time to make a scientifically
defensible conclusion about the extent of the
active faults into the Jackson Purchase Region.
Much more time is needed for seismic
monitoring in the area. The observed seismicity
suggests, however, that the active
faults of the New Madrid Seismic Zone may
not extend into the Jackson Purchase Region.
This could result in lower estimates of the
seismic hazard in western Kentucky.